Multiplication Properties

Using Multiplication Properties

You will learn:

To identify and use multiplication properties.

Why learn this?

Multiplication properties help when you use mental math.

Stacy has 8 shelves. She has 5 CDs on each shelf. Bjorn has 5 shelves. He has 8CDs on each shelf. Who has more CDs?

So, Stacy and Bjorn have the same number of CDs.















QUESTIONS

• Write the name of the multiplication property used in each number sentence.

1. 2 x (4 x 3) = (2 x 4) x 3
2. 5 x 4 = 4 x 5
3. (7 x 3) x 8 = 7 x (3 x 8)
   • Vanessa:
   1. associative property of multiplication
   2. commutative property of multiplication
   3. associative property of multiplication

[Dalia] 1) associative, 2) communicative, 3) associative.

Nasser:

1) Associative property of multiplication
2) Commutative property of multiplication
3) Associative property of multiplication


Jida:
1) Associative property
2)Commutative property
3)Associative property

• Copy and complete the equation. Identify the property used.

1. 4 x 6 = 6 x _
2. 5 x (4 x 6) = (5 x _ ) x 6
3. _ x 7 = 7 x 4
   • Vanessa:
   1. 4 x 6 = 6 x 4 ; commutative property of multiplication
   2. 5 x (4 x 6) = (5 x 4) x 6 ; associative property of multiplication
   3. 4 x 7 = 7 x 4 ; commutative property of multiplication

[Dalia] 1) communicative: 4 x 6 = 6 x 4, 2) associative: 5 x (4 x 6) = (5 x 4) x 6, 3) communicative: 4 x 7 = 7 x 4

Nasser:

1) 4 x 6 = 6 x 4 --> Commutative
2) 5 x (4 x 6) = (5 x 4) x 6 --> Associative
3) 4 x 7 = 7 x 4 --> Commutative


Jida:

1) 4x6=6x4 commutative
2) 5x(4x6)=(5x4)x6 associative
2) 4x7=7x4 commutative

• Karl has 7 dimes in each of 6 rows. Sue has 6 dimes in each of 7 rows. Who has more money? Show your work.
  • Vanessa:
    1. Karl: 7 x 6 = 42 & Sue: 6 x 7 = 42 ; both have the same amount of money.

[Dalia]

Karl Sue
7 (dimes) x 6 (rows) I 6 (dimes) x 7 (rows)
7 x 6 I 6 x 7
(communicative property)

Both have the same amout of money: 42 dimes.

Nasser:

Karl 7 x 6= 42 dimes Sue 6 x 7= 42 dimes

7 x 6 = 6 x 7 (Commutative)

Both have 42 dimes.


Jida:

1) Sue has : 6x7 = 42
Karl has : 7x6= 42
they both have 42 dimes.